模块增强剂的逐步修改是Drosophila种群适应的基础
Mark Rebeiz1, John E Pool, Victoria A Kassner
1Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, WI 53706, USA.
Science (New York, N.Y.)
|December 19, 2009
概括
动物特征的进化涉及 cis 调节元素的变化,称为增强剂. 这项研究揭示了增强剂中的多个突变如何在Drosophila中产生显著的适应性特征.
科学领域:
- 进化生物学是进化的生物学.
- 发育遗传学的发展遗传学.
- 分子进化的分子进化.
背景情况:
- 动物形态的进化受到控制发育调节基因的cis调节元件 (增强剂) 变化的显著影响.
- 导致增强剂功能的改变的特定突变途径,包括突变的数量,起源,效果和顺序,仍然在很大程度上是未知的.
研究的目的:
- 为了阐明增强器进化的突变路径.
- 在乌干达的Drosophila群体中,通过分析树的增强剂来研究适应性黑色素的遗传基础.
主要方法:
- 定位一个套件的替代在一个模块化增强器的青木locus.localization.
- 分析导致表型变化的突变的起源,影响和组合.
主要成果:
- 在树增强剂中发现了至少五种最近的突变.
- 这些突变源于既有常态变异,又有新突变.
- 这些突变的综合作用导致显著的表型变化,有助于适应性忧郁症.
结论:
- 增强剂是不同的宏分子实体,与蛋白质序列相比具有不同的功能约束.
- 来自各种来源的多个突变可以快速结合,产生具有较大的表型效应的等位基因,推动适应性进化.
相关概念视频
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...